地铁车站设备区空调负荷动态特性分析及系统优化

通过对广州地铁某车站设备区的研究,分析全年逐时空调负荷计算和空调机组运行负荷的动态变化状况,得出地铁车站设备区空调实际负荷特性及机组冷冻水进、出水温差、设备区室内温度、室内焓值等各项性能参数的变化规律,并以此对地铁车站设备区通风空调负荷的常用工程设计及运行模式进行评估,对地铁设备区通风空调系统提出优化建议、改进措施以及可行和节能的系统运行方案。     

铁路客车空调负荷研究

采用非稳定传热计算法分别计算了南北向和东西向,以及夕发朝至运行时硬座空调客车的动态负荷。计算结果表明,受外界环境的影响,铁路空调客车在运行时空调负荷变化较大,在不同区间运行的铁路客车,其空调动态负荷的最大值不尽相同。因此认为,不能仅依据TB1951—87《客车空调设计参数》来确定空调机组制冷量,而应根据客车运行区间的最大动态负荷设计空调机组；若能根据客车动态负荷变化趋势,实现客车空调机组的变频调节和自动控制,可达到提高客车舒适度和节能的目的。     

铁路客车空调负荷研究

采用非稳定传热计算法分别计算了南北向和东西向，以及夕发朝至运行时硬座空调客车的动态负荷。计算结果表明，受外界环境的影响，铁路空调客车在运行时空调负荷变化较大，在不同区间运行的铁路客车，其空调动态负荷的最大值不尽相同。因此，不能仅依据TB1951—87来确定空调机组制冷量，而应根据客车运行区间的最大动态负荷设计空调机组；同时，若能根据客车动态负荷变化趋势，实现客车空调机组的变频调节和自动控制，可达到提高客车舒适度和节能的目的。     

空调系统变水温调节的特性实验及节能分析

针对中、小型中央空调系统，根据空调系统大多数时间处于部分负荷下运行的特点，通过实验，分析了变水温调节时冷水机组和空调系统的运行特性：以实验结果为依据，对中央空调系统的节能潜力进行了分析。     

办公楼变频空气源热泵序列优化控制

为了满足公共建筑中空调系统部分负荷下的节能运行调节需求,制冷机房经常配置多台冷水机组。空调系统中冷水机组能耗占比较高,而机组序列控制在系统满足室内负荷需求与节能中运行起关键作用。为了提高热泵机组的运行能效,本文提出一种空气源热泵机组的序列优化控制方法。首先建立变频空气源热泵机组模型,然后建立多台同型号机组序列优化控制目标函数,同时给出实时建筑负荷下求解机组最佳运行序列组合的算法与步骤。以某工程为例,利用e QUEST软件分析了办公楼全年的空调负荷变化,并在夏季、冬季典型日负荷基础上,对比分析了热泵机组序列优化控制策略与传统策略。结果表明:与传统策略相比,在10%~100%的系统部分负荷范围内,采用序列优化控制策略的机组能耗平均降低13.4%。在夏季典型日,热泵机组能耗降低14.5%;在冬季典型日,热泵机组能耗降低12.3%;在过渡季典型日,热泵机组能耗降低3.3%。在供冷季,采用机组序列优化控制策略能耗降低14.1%;在供热季能耗降低9.0%。热泵机组的序列优化控制策略具有明显的节能效果。     

武汉地区地铁列车空调全年负荷特性分析

列车空调实时负荷不仅随车外气象参数变化,还受到车内人员密度频繁变化的影响。以武汉为例,基于传热学原理,结合武汉地区气象资料,参考已有的客流量实时统计数据,对武汉地铁列车车辆空调全年实时负荷进行了计算分析,以探索武汉地区的列车空调的负荷特性,指导该地区地铁列车热泵空调机组的设计。研究结果表明,武汉地区地铁列车空调制冷季的负荷与采暖季的负荷比值约为2.65,热泵机组应基于制冷需求设计。空调机组大多数时间在部分负荷下运行,满负荷工况较少。新风负荷在负荷占比中超过60%,是地铁列车空调节能重点。     

大金变频控制热泵式VRV空调机组制冷运行特性的实验研究

本文对大金变频控制热泵式VRV控调系统夏季制冷运行时的节能性作了一系列实验研究,得到了VRV空调系统的夏季部分负荷运转特性,并在节能方面与普通风冷热泵冷热水机组作了比较,证明该空调机组比普通冷热水机组节能。     

变风量空调系统负荷计算及设备风量计算对比分析

对一建筑物进行了变风量空调系统设计,对变风量空调系统负荷计算的方法进行阐述,对不同空气处理机组的配置形式算出空气处理机组的风量,并做比较。认为准确计算逐时负荷计算是变风量空调系统设计的重要一步,且不同的空气处理机组的配置方式对于系统节能有着不同的效果。     

发电厂循环水泵的优化调度及应用

[摘要]本文通过改变循环水泵组合运行方式对循环水流量进行调节,在满足机组负荷变化运行对背压需要的前提下,根据A发电公司所处地理位置,和夏季温度较高,冬天温度较低的变化情况,研究凝汽器真空度变化、和汽轮机凝结水温升变化等计算方法,得到循环水泵的节能运行方式,实现机组节能优化目标。     

超临界机组完全变压运行技术与节能探讨

根据系统分析,超临界机组完全变压运行技术室采用调节变凝结水流量的方式来快速调节机组负荷,实现显著的节能减排效果。本文对变凝结水流量调节机组负荷的大致范围及原理等进行了分析,提出了变凝结水流量调节方式所存在的优点和问题,认为只有将传统技术与变凝结水流量调节机组技术相结合,才能实现超临界机组完全变压运行技术,这种技术对大型燃煤机组的节能减排有很重要的意义。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.